Cephradine for Injection
» Cephradine for Injection contains not less than 90.0 percent and not more than 115.0 percent of the labeled amount of cephradine, calculated as the sum of cephradine (C16H19N3O4S) and cephalexin (C16H17 N3O4S).
Packaging and storage— Preserve in Containers for Sterile Solids as described under Injections 1.
USP Reference standards 11
USP Cephradine RS Click to View Structure
USP Cephalexin RS Click to View Structure
USP Endotoxin RS
Constituted solution— At the time of use, it meets the requirements for Constituted Solutions under Injections 1.
Identification— Dilute the contents of 1 container of Cephradine for Injection with water to obtain a test solution containing about 3 mg of cephradine per mL. Proceed as directed in the Identification test under Cephradine Capsules, beginning with “Place a suitable thin-layer chromatographic plate”: the RF value of the principal spot obtained from the test solution corresponds to that obtained from the Standard solution.
Bacterial endotoxins 85 It contains not more than 0.20 USP Endotoxin Unit per mg of cephradine.
Sterility 71 It meets the requirements when tested as directed for Membrane Filtration under Test for Sterility of the Product to be Examined.
pH 791: between 8.0 and 9.6, in a solution containing 10 mg per mL.
Loss on drying 731 Dry about 100 mg, accurately weighed, in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5 mm of mercury at 60 for 3 hours: it loses not more than 5.0% of its weight.
Particulate matter 788: meets the requirements for small-volume injections.
Other requirements— It meets the requirements for Uniformity of Dosage Units 905 and Labeling under Injections 1.
Assay—
Mobile phase, Standard preparation, Resolution solution, and Chromatographic system— Proceed as directed in the Assay under Cephradine.
Assay preparation 1 (where it is represented as being in a single-dose container)—Constitute Cephradine for Injection in a volume of water, accurately measured, corresponding to the volume of solvent specified in the labeling. Withdraw all of the withdrawable contents, using a suitable hypodermic needle and syringe, and dilute quantitatively with Mobile phase to obtain a solution containing about 0.5 mg of cephradine per mL.
Assay preparation 2 (where the label states the quantity of cephradine in a given volume of constituted solution)—Constitute Cephradine for Injection in a volume of water, accurately measured, corresponding to the volume of solvent specified in the labeling. Dilute an accurately measured volume of the constituted solution quantitatively with Mobile phase to obtain a solution containing about 0.5 mg of cephradine per mL.
Procedure— Separately inject equal volumes (about 10 µL) of the Standard preparation and Assay preparation 1 or Assay preparation 2 into the chromatograph, record the chromatograms, and measure the responses for the major peaks. Calculate the quantity, in mg, of cephradine (sum of cephradine and cephalexin) withdrawn from the container, or in the portion of constituted solution taken by the formula:
(CP)(L / 1000D)(rU / rS)
in which C is the concentration, in mg per mL, of USP Cephradine RS in the Standard preparation; P is the designated potency, in µg per mg, of USP Cephradine RS; L is the labeled quantity, in mg of cephradine, in the container taken to prepare Assay preparation 1, or in the volume of constituted solution taken to prepare Assay preparation 2; D is the concentration, in mg of cephradine per mL, of Assay preparation 1 or Assay preparation 2, based on the labeled quantity in the container or in the portion of constituted solution taken, respectively, and the extent of dilution; and rU and rS are the sums of the cephradine and cephalexin peak responses obtained from Assay preparation 1 or Assay preparation 2 and the Standard preparation, respectively.
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USP35–NF30 Page 2595